<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>cn.mepu</groupId>
    <artifactId>mybatis_build</artifactId>
    <version>1.0-SNAPSHOT</version>
<!--指定打包方式-->
    <packaging>jar</packaging>
<!--    导入mybatis依赖-->
    <dependencies>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.3</version>
        </dependency>
<!--        导入mysql依赖-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.6</version>
        </dependency>
<!--        导入log4j-->
        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.16</version>
        </dependency>
<!--        导入junit-->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.10</version>
            <scope>test</scope>
        </dependency>
    </dependencies>

</project>

package cn.mepu.domain;

import java.io.Serializable;

/** * @author shkstart * @create 2019-11-04 9:45 */public class User implements Serializable {    private int id;    private String name;    private int age;

    public int getId() {        return id;    }

    public void setId(int id) {        this.id = id;    }

    public String getName() {        return name;    }

    public void setName(String name) {        this.name = name;    }

    public int getAge() {        return age;    }

    public void setAge(int age) {        this.age = age;    }

    @Override    public String toString() {        return "User{" +                "id=" + id +                ", name='" + name + '\'' +                ", age=" + age +                '}';    }}

package cn.mepu.Dao;

import cn.mepu.domain.User;

import java.util.List;

/**
 * @author shkstart
 * @create 2019-11-04 9:50
 */
public interface UserDao {
    /**
     * 查询所有用户
     * @return
     */
    List<User> findAll();
}

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>
    <environments default="mysql">
        <environment id="mysql">
            <transactionManager type="JDBC"></transactionManager>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/javaee"/>
                <property name="username" value="root"/>
                <property name="password" value="root"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
<!--        定义配置映射-->
        <mapper resource="cn/mepu/Dao/UserDao.xml"></mapper>
    </mappers>
</configuration>

 <?xml version="1.0" encoding="UTF-8" ?>
 <!DOCTYPE mapper
         PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
         "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
 <!--定义映射接口-->
 <mapper namespace="cn.mepu.Dao.UserDao">
 <!-- id = dao接口方法名称 resultType=数据封装对象   -->
     <select id="findAll" resultType="cn.mepu.domain.User">
         select * from user
     </select>
 </mapper>

 package cn.mepu;

 import cn.mepu.Dao.UserDao;
 import cn.mepu.domain.User;
 import org.apache.ibatis.io.Resources;
 import org.apache.ibatis.session.SqlSession;
 import org.apache.ibatis.session.SqlSessionFactory;
 import org.apache.ibatis.session.SqlSessionFactoryBuilder;

 import java.io.IOException;
 import java.io.InputStream;
 import java.util.List;

 /**
  * @author shkstart
  * @create 2019-11-04 10:02
  */
 public class mybatisTest {
     public static void main(String[] args) throws IOException {
         //1.读取配置文件
         InputStream in = Resources.getResourceAsStream("SqlMapConifg.xml");
         //2.创建SqlSessionFactory工厂
         SqlSessionFactory factory = new SqlSessionFactoryBuilder().build(in);
         //3.使用工厂生产SqlSession对象
         SqlSession sqlSession = factory.openSession();
         //4.使用SqlSession创建Dao接口代理对象
         UserDao userDao = sqlSession.getMapper(UserDao.class);
         //5.使用代理对象执行方法
         List<User> users = userDao.findAll();
         for (User user : users) {
             System.out.println(user);
         }
         //6.释放资源
         sqlSession.close();
         in.close();
     }
 }